a Frontiers of Biogeography 2021, 13.3, e53226 Frontiers of Biogeography REVIEW the scientific journal of the International Biogeography Society High-elevation limits and the ecology of high-elevation vascular plants: legacies from Alexander von Humboldt1 H. John B. Birks1,2* 1 Department of Biological Sciences and Bjerknes Centre for Climate Research, University of Bergen, PO Box 7803, Bergen, Norway; 2 Ecological Change Research Centre, University College London, Gower Street, London, WC1 6BT, UK. *Correspondence: H.J.B. Birks,
[email protected] 1 This paper is part of an Elevational Gradients and Mountain Biodiversity Special Issue Abstract Highlights Alexander von Humboldt and Aimé Bonpland in their • The known uppermost elevation limits of vascular ‘Essay on the Geography of Plants’ discuss what was plants in 22 regions from northernmost Greenland known in 1807 about the elevational limits of vascular to Antarctica through the European Alps, North plants in the Andes, North America, and the European American Rockies, Andes, East and southern Africa, Alps and suggest what factors might influence these upper and South Island, New Zealand are collated to provide elevational limits. Here, in light of current knowledge a global view of high-elevation limits. and techniques, I consider which species are thought to be the highest vascular plants in twenty mountain • The relationships between potential climatic treeline, areas and two polar regions on Earth. I review how one upper limit of closed vegetation in tropical (Andes, can try to